Аннотация:The article considers various aspects of the evolution of close binary systems (CBSs). The variation in the orbital parameters of a CBS during its evolution, including the evolution of the CBS under the influence of the magnetic stellar wind and the gravitational wave radiation, is analyzed. The evolution of CBSs with mass transfer is considered. Evolutionary scenarios for CBSs and population synthesis are discussed. Modern three-dimensional models of gas flow in interacting CBSs are presented. The collision of supersonic stellar winds in CBSs is discussed.